History of the Flight
The aircraft, a Jetstream 4102 registered G-MAJV, departed from Aberdeen on 9 April 2008 at 0804 UTC for a non-scheduled commercial passenger flight to Vagar in the Faroe Islands. The crew consisted of two pilots and one cabin crew member. The commander, aged 63, held an Airline Transport Pilot's Licence and had 12,000 flying hours, including 4,000 on type. The co-pilot was fully fit.
Pre-flight Conditions and Decisions
The weather at Aberdeen was inclement, with snow falling and lying on the ground at a temperature of 0°C. The aircraft was parked on a remote stand. The commander noted loose contaminants on the airframe but no visible ice. Despite intending to de-ice, delays led to the decision to have the aircraft swept manually. Ground staff swept the wings and gave a 'thumbs up' signal; the commander assumed the tail section was also cleared. The crew checked flight controls during taxi, noting slightly heavier feel but deemed normal.
In-flight Event
The aircraft took off and climbed into cloud at about 200 ft. As it passed FL90, the autopilot pitch trim warning activated. The commander disengaged the autopilot and found the elevators immovable, while the ailerons and rudder were free. The crew declared a MAYDAY and diverted toward Wick, where the weather was clearer. They applied strong forces to the control columns and used power changes to gain some pitch control. The aircraft descended into warmer air, and at about 4,000 ft amsl the controls suddenly freed. A handling check confirmed full control.
Landing and Aftermath
The aircraft landed at Wick without difficulty. Eyewitnesses saw material fall from the tail, and runway inspection revealed large ice fragments. Post-flight inspection showed ice in the elevator hinges. The aircraft sustained no damage, and no injuries were reported.
Investigation Findings
The AAIB investigation noted that the elevator became jammed by ice during climb due to inadequate de-icing and anti-icing. The commander's fitness to fly, as he was recovering from a cold and had slept poorly, coupled with potential pressures to operate the flight, were identified as contributory factors. Two Safety Recommendations were made.